Shift and shift lock mechanism for typewriter

ABSTRACT

A shift mechanism for a typewriter having a shift key and a shift lock key, both of which are effective to shift the typewriter carriage. A latching arm is normally spring-biased to a nonlatching position and is rocked forwardly to a latching position when the shift lock key is operated to retain the carriage in shifted position until the shift key is operated to release the latching force on the latch arm to permit it to be biased to a nonlatching position for release of the carriage from the shifted position.

United States Patent [72] Inventor Shigeaki Kuramochi Tokyo, Japan [21]Appl. No. 791,278 [22] Filed Jan. 15, 1969 [45] Patented Mar. 30, 1971[73] Assignee Louis Marx & Co., Inc.

New York, N.Y.

[54] SHIFT AND SHIFT LOCK MECHANISM FOR TYPEWRITER 6 Claims, 4 DrawingFigs.

[52] U.S. Cl 197/73, 197/80 [51] Int. Cl B4lj 11/14, B4 1 j 29/64 [50]Field ofSearch 197/71, 72, 73, 79, 80

[56] References Cited UNITED STATES PATENTS 984,284 2/1911 McBirney197/81 1,227,438 5/1917 Hess 197/79 1,448,411 3/1923 Lehmann 197/791,475,664 11/1923 Utz 197/79 2,251,122 7/1941 Dobson..... 197/732,705,553 4/1955 Thomson 197/22 Primary Examiner-Ernest T. Wright, Jr.Assistant Examiner-Stephen C. Pellegrino Attorney-Blum, Moscovitz,Friedman and Kaplan ABSTRACT: A shift mechanism for a typewriter havinga shift key and a shift lock key, both of which are effective to shiftthe typewriter carriage. A latching arm is normally spring-biased to anonlatching position and is rocked forwardly to a latching position whenthe shift lock key is operated to retain the carriage in shiftedposition until the shift key is operated to release the latching forceon the latch arm to permit it to be biased to a nonlatching position forrelease of the carriage from the shifted position.

Patented March so, 1971 3,572,488

2 Shea ts-Sheet 1 F/GJ M'VMN'I'OH. SHIGEAKI KURAMOCHI Patented March 30,1971 2 Sheets-Sheet 2 SHIFT AND SHIFT LOCK MECHANISM FOR TYPEWRITERBACKGROUND OF THE INVENTION This invention relates generally to a shiftmechanism for a typewriter and is more particularly directed to a shiftlock mechanism cooperating with the carriage shifting mechanism forretaining the carriage in shifted position. While typewriter carriageshifts and shift locksare known in the art, the mechanism of the instantinvention is of simplified and inexpensive construction to permit theincorporation of such mechanism in relatively inexpensive typewriters ofthe type that are sold for juvenile use. Due to the use of suchtypewriters, such typewriters must be inexpensively constructed but arepreferably designed to simulate the operation of standard commercialtypewriters so that the child will develop a familiarity withtypewriters, will learn to type and will be able to make the transitionto a standard typewriter as he becomes older.

SUMMARY OF THE INVENTION Generally speaking, in accordance with theinvention, a simplified shift and shift lock mechanism is provided whichis especially suitable for incorporation in a juvenile typewriter ofinexpensive construction. The shift and shift lock mechanism duplicatesthe operation of similar mechanisms on standard typewriters. To retainthe carriage in a shifted .position, a latching arm is provided which isnormally biased to a nonlatching position and which is controlled by ashift lock key for advancement to a latching position. Bias of thelatching arm to the nonlatching position is overcome by engagement ofthe arm with a portion of the typewriter frame with the latching armbeing held in engagement as a result of the force applied thereto by thetendency of the carriage to move from the shifted position. When suchforce is overcome by operation of a shift key, the latching arm ispermitted to move to the nonlatching position and the carriage can thenreturn to the normal position when the shift key is released. 7

Accordingly, it is an object of this invention to provide a shiftmechanism for a typewriter of improved and simplified construction.

Another object of the invention is to provide a shift lock mechanism fora typewriter which utilizes a latching arm which is normally biased to anonlatching position and which is held in a latching position as aresult of forces applied from the carriage when the carriage is in theshifted position.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts which will beexemplified in the construction hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of theinvention, reference is had to the following description taken inconnection with the accompa'nying drawing, in which:

FIG. 1 is a partial sectional side elevational view of a typewriterincorporating a shift mechanism constructed in ac cordance with apreferred embodiment of the instant inven tion;

FIG. 2 is a partial elevational view of a preferred embodiment of theshift mechanism in shift lock position with elements being omitted forthe sake of clarity;

FIG. 3 is a partial sectional view taken along line 3-3 of FIG. 1; and

FIG. 4 is a partial sectional view taken along line M of FIG. il.

DESCRIPTION OF THE PREFERRED EMBODIMENT While the shift mechanism of theinstant invention is suitable for use in substantially any type oftypewriter or other business machine requiring carriage shift, themechanism disclosed herein is shown as incorporated in a typewriter ofthe type disclosed in U.S. Pat. No. 3,338,369 issued Aug. 29, 1967 inthe name of Willis E. Rexford. A complete disclosure of such typewriteris found in the aforesaid Rexford patent and thus, for simplicity, theinstant disclosure is generally limited to the elements required fordisclosure of the preferred embodiment of the shift mechanism. A frame11 includes, at the rear end, a rear wall 12 and a base wall 13. Theframe 11 also includes, at the front end, comb elements M and a keyboard15. A carriage assembly indicated generally at 16 is supported from rearwall 12 as willihereafter be described. A housing 17 envelops the frame11 to impart an attractive and finished appearance to the typewriter.

A plurality of keys 13 are slidably received in keyboard 15 and projectthrough the housing to define the keyboard of the typewriter.

Carriage assembly 16 includes a platen portion 19 which slidestransversely with respect to a support section 21 via opposed,interengaging channels 22. A spring pulley 23 secured to support section2l biases the platen portion 19 in a letter space direction undercontrol of an escapement mechanism (not shown).

In order to shift the carriage assembly 16, the entire carriage assembly1ti.must be raised and, for this purpose, posts 24lare secured to theframe 11 parallel to rear wall 12 and secured to base wall 13. Supportsection 21 is slidably mounted on posts 24 whereby the carriage assembly16 is guided for movement between a lowered and a raised position.

At each side of the typewriter, a link mechanism is provided for furtherguidance of the carriage assembly 16. Lugs 25 projecting rearwardly ofrear wall 12 pivotally receive a rod 26 extending along the rear of therear wall 12. At each side of the typewriter, a first link 27 has oneend secured to rod 26. The other end is pivoted to one end of a secondlink 28 whose opposite end is pivoted to support section 21 as at pivot29. With the pivoted links 27 and 23 provided at each side of thetypewriter and pivoted at one end to support section 21 and secured atthe other end to rod 26, each end of the carriage assembly 16 is raisedby an equal amount when the carriage assembly 16 is lifted from one endonly.

As in standard typewriters, a shift key 31 is provided at each side ofthe keyboard and, since the shifting mechanism (not the shift lockmechanism) is the same at each side of the typewriter, one of theshifting mechanisms will now be described. A shift key 31 is slidablymounted through keyboard 15 and engages with one end of a key lever 32for operating the key lever 32. Key lever 32 is pivoted at 33 to thecomb elements 14 substantially at the'intersection of the three arms ofthe key lever 32. A rearwardly extending arm of the key lever 32 isbiased by a spring 34 connected to a portion of the frame 11 whereby thekey lever 32 is biased to its normal position with shift key 31 in theraised position. The third arm of key lever 32 has one end of a wirelink 35 pivoted at the end thereof. It can be seen from FIG. 1 that,when shift key 31 is depressed, the key lever 32 is rotated in aclockwise direction thereby moving wire link 35 in a forward directionas indicated by the arrow. Spring 34 biases the key lever 32 and wirelink 35 in the reverse direction when shift key 31 is released.

As best seen in FIGS. 3 and 4, a pair of lugs 36 project upwardly frombase wall 13. Pivotally mounted through lugs 36 is a shifting rod 37having a rearwardly extending end 38 and an upwardly extending end 39.The rearwardly extending end 38 is positioned beneath and in contactwith support section 21 and to the outer end of upwardly extending end39 is pivoted the rear end of wire link 35. As shown in FIG. 1, when theshift key 31 is depressed and wire link 35 is moved in the direction ofthe arrow, shifting rod 37 is rotated in a clockwise direction, causingrearwardly extending end 38 to move upwardly in an arc to raise supportsection 21 and the carriage assembly 16 to a shifted position. The shiftposition will be retained so long as shift key 31- remains depressedand, under gravity, the carriage assembly 16 will return to the normalposition when the shift key 31 is released. Note that a spring 41secured between first link 27 and the upper end of rear wall 12 providesa counterbalance for the weight of the carriage assembly 16 in order toreduce the amount of force required to shift the carriage assembly 16through shift key 31. As aforenoted, the shifting mechanism hereinabovedescribed is duplicated on both sides of the typewriter so that thecarriage assembly 16 may be shifted with either hand. The utilization ofthe first and second links 27 and 28 located at each side of thetypewriter connected to a common rod 26 assures that both sides of thecarriage assembly 16 will be shifted an equal amount regardless of whichshift key 31 is depressed.

In order to lock the carriage assembly 16 in shifted position, it hasbecome common practice to provide a shift lock operable from one side ofthe typewriter only, usually the left side of the keyboard and, in orderto more nearly simulate standard typewriters, the instant inventionprovides a single shift lock mechanism preferably located on the leftside of the keyboard 15. To this end, a shift lock key 42 is slidablymounted in keyboard 15 in engagement with one end of a key lever 43pivoted to comb elements 14 and substantially identical to key lever 32.The shift mechanism also includes a spring 44 (FIG. 2) for biasing theshift lock key lever 43 to the normal position.

To the upper end of one of the arms of key lever 43 is pivoted one endof a wire link 45, the other end of which is pivoted to the latching arm46, as will now be described.

Latching arm 46 is shown in the normal nonoperating position in FIG. 1and in the carriage shift locked position in FIG. 2. A plate 47 ispivoted intermediate its end as at 48 to upwardly extending end 39 ofthe shifting rod 37 intermediate the length of the upwardly extendingend 39. At the lower end of plate 47 there is provided an inwardlyextending arm 49 (FIG. 3) which overlies upwardly extending end 39 andlimits relative rotation between plate 47 and the upwardly extending end39 in the clockwise direction when viewed in FIG. 2. Intermediate theends of latching arm 46 but proximate to the rear end thereof, a pivot51 pivotally connects the latching arm 46 to the upper end of plate 47.Rearwardly of the pivot 51, a spring 52 acts between latching arm 46 andthe lower end of plate 47 to bias the latching arm 46 in thecounterclockwise direction as viewed in FIGS. 1 and 2.

The rear end of wire link 45 is pivotally connected to the latching arm46 above pivot 51 as at 53.

The forward end of latching arm 46 extends through an aperture 54 in anintermediate wall 55 which forms part of frame 11. Note that wire links35 and 45 also extend with clearance through aperture 54. Proximate tothe outer end of latching arm 46 is a latch portion 56 adapted to engagewith the lower edge of aperture 54 to act as a detent for retaining thecarriage assembly 16 in shift lock position.

The operation of the shift mechanism may now be described. When it isdesired to shift the carriage assembly 16 without locking same, shiftkey 31 is depressed thereby, through key lever 32 and wire link 35,rotating shifting rod 37 in the clockwise direction as viewed in FIG. 1to raise the carriage assembly 16. Since the shift lock key 42 is notdepressed, key lever 43 tends to remain stationary under the action ofspring 44 whereby wire link 45 restrains latching arm 46 against forwardmovement. As upwardly extending end 39 moves toward intermediate wall 55it carries with it pivot 48 to move forwardly the lower portion of plate47. Plate 47 is permitted to move forwardly in an are due to pivot 51even though latching arm 46 remains substantially stationary andwithdrawn from a latching position. Also, the bias on latching arm 46 byspring 52 holds the latching arm 46 in a raised, nonlatching position.

When it is desired to lock the shift or lock the carriage assembly 16 inthe raised position, shift lock key 42 is depressed, effecting arotation of key lever 43 and forward movement of the wire link 45. Theforward movement of the wire link 45 first rotates latching arm 46 inthe clockwise direction about pivot 51 and against the action of spring52 to bring the lower forward end of the latching arm 46 into engagementwith the lower edge of aperture 54 thereby arresting further clockwiserotation of the latching arm 46. Continued movement of wire link 45causes plate 47 to be rotated in the clockwise direction until arm 49abuts a portion of the upwardly extending end 39 of shifting rod 37 andthereafter continued forward movement of wire link 45 rotates theshifting rod 37 to raise the carriage assembly 16 to the shiftedposition. As the carriage assembly 16 approaches the fully raisedposition, latch portion 56 projects through aperture 54 and engages overintermediate wall 55. Engagement is assured as a result of the continuedforce applied to the latching arm 46 to rotate it in the clockwisedirection through wire link 45. Shift lock key 42 may now be releasedand the weight of the carriage assembly 16 tends to cause reversemovement of the elements. However, with latch portion 56 engaged overthe intermediate wall 55, the latching engagement maintains the latchingconnection and the carriage assembly 16 is thus held in the shiftedposition.

When it is desired to lower the carriage assembly 16 and release theshift lock, shift key 31 is depressed to slightly rotate shifting rod 37in the clockwise direction. This effects a release of the holding forcesapplied to latching arm 46 and, since shift lock key 42 is notdepressed, no forward movement is applied to the wire link 45 and thusno force is applied to bias latching arm 46 in the clockwise direction.With shift key 31 depressed, spring 52 immediately rotates latching arm46 in the counterclockwise direction to raise it above the lower edge ofaperture 54 whereby, upon release of shift key 31, the latching arm 46may be withdrawn from its latching position through intermediate wall 55and the carriage assembly 16 may be lowered to its normal position.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above construction withoutdeparting from the spirit and scope of the invention, it is intendedthat all matter contained in the above description or shown in theaccompanying drawing shall be interpreted as illustrative and not in alimiting sense.

Iclaim:

I. In a typewriter or like machine, in combination, a frame having frontand rear ends, a carriage assembly, carriage assembly mounting meansmovably mounting said carriage assembly proximate the rear end of saidframe, said carriage assembly being movable between a lowered normalposition and a raised shifted position, shift means mounted to saidframe and cooperating with said carriage assembly for raising saidcarriage assembly to said shifted position, said shift means includingan operating element, a shift key at said front end of said frame, afirst key lever pivoted to said frame and operatively associated withsaid shift key, first link means connected between said first key leverand said operating element for moving said carriage assembly to saidshifted position an operation of said shift key, latching means pivotedto said operating element and including a forwardly projecting latchportion, means defining a latching surface on said frame, said latchingmeans being movable between a latching position adapted for engagementwith said latching surface and a nonlatching position, spring meansbiasing said latching means to said nonlatching position, a shift lockkey at said front end of said frame, a second key lever pivoted to saidframe and operatively associated with said shift lock key, and secondlink means connected between said second key lever and said latchingmeans for moving said latching means to said latching position whileconcurrently moving said carriage assembly to said shifted position onoperation of said shift lock key.

2. In a typewriter or like machine, the combination as claimed inclaim 1wherein said latching means includes a plate pivoted to said operatingelement and a latching arm pivoted to said plate, said forwardlyprojecting latching portion being provided on said latching arm.

3. In a typewriter or like machine, the combination as claimed in claim2 wherein said spring means is connected between said latching arm andsaid plate whereby to bias said latching arm to said nonlatchingposition.

4. In a typewriter or like machine, the combination as claimed in claim2 wherein said means defining a latching surface includes anintermediate wall on said frame and means defining an aperturetherethrough, saidlatching arm projecting through said aperture.

5. In a typewriter or like machine, the combination as claimed in claim2 wherein said operating element, said plate and said latching arm aremovable in planes parallel to one another.

6. In a typewriter or like machine, the combination as claimed in claim2 wherein said plate includes an abutment arm projecting in the path ofmovement of said operating element whereby to limit relative rotation inone direction of said plate with respect to said operating element aboutthe pivot of said plate to said operating element.

1. In a typewriter or like machine, in combination, a frame having frontand rear ends, a carriage assembly, carriage assembly mounting meansmovably mounting said carriage assembly proximate the rear end of saidframe, said carriagE assembly being movable between a lowered normalposition and a raised shifted position, shift means mounted to saidframe and cooperating with said carriage assembly for raising saidcarriage assembly to said shifted position, said shift means includingan operating element, a shift key at said front end of said frame, afirst key lever pivoted to said frame and operatively associated withsaid shift key, first link means connected between said first key leverand said operating element for moving said carriage assembly to saidshifted position an operation of said shift key, latching means pivotedto said operating element and including a forwardly projecting latchportion, means defining a latching surface on said frame, said latchingmeans being movable between a latching position adapted for engagementwith said latching surface and a nonlatching position, spring meansbiasing said latching means to said nonlatching position, a shift lockkey at said front end of said frame, a second key lever pivoted to saidframe and operatively associated with said shift lock key, and secondlink means connected between said second key lever and said latchingmeans for moving said latching means to said latching position whileconcurrently moving said carriage assembly to said shifted position onoperation of said shift lock key.
 2. In a typewriter or like machine,the combination as claimed in claim 1 wherein said latching meansincludes a plate pivoted to said operating element and a latching armpivoted to said plate, said forwardly projecting latching portion beingprovided on said latching arm.
 3. In a typewriter or like machine, thecombination as claimed in claim 2 wherein said spring means is connectedbetween said latching arm and said plate whereby to bias said latchingarm to said nonlatching position.
 4. In a typewriter or like machine,the combination as claimed in claim 2 wherein said means defining alatching surface includes an intermediate wall on said frame and meansdefining an aperture therethrough, said latching arm projecting throughsaid aperture.
 5. In a typewriter or like machine, the combination asclaimed in claim 2 wherein said operating element, said plate and saidlatching arm are movable in planes parallel to one another.
 6. In atypewriter or like machine, the combination as claimed in claim 2wherein said plate includes an abutment arm projecting in the path ofmovement of said operating element whereby to limit relative rotation inone direction of said plate with respect to said operating element aboutthe pivot of said plate to said operating element.